CN107159171A - A kind of preparation method of quaternized Nano diamond agglomeration graft type anion chromatographic filling material - Google Patents

Abstract

A preparation method for quaternized nano-diamond agglomeration grafted anion chromatographic filler, comprising the following steps: (a) synthesizing monodisperse linear polystyrene microspheres with particle diameters between 1 and 3 μm; (b) using Single-step seed swelling method to synthesize monodisperse polystyrene-divinylbenzene microspheres with a particle size between 6-10 μm; (c) preparation of quaternized nano-diamond colloid; (d) polystyrene-divinylbenzene Vinylbenzene microspheres are sulfonated to make the surface negatively charged, and then combined with positively charged quaternized ammonium nano-diamond colloids through electrostatic interaction to obtain an agglomerated anion exchange packing; then methylamine and 1,4‑ Butanediol diglycidyl ether is used as a raw material to carry out grafting reaction on the microsphere surface of the agglomeration type anion exchange filler to obtain the quaternized nanometer diamond agglomeration graft type anion chromatography filler. The anion chromatographic filler prepared by the invention has the advantages of good mechanical strength, good stability, controllable exchange capacity, high separation degree, strong acid and alkali resistance and the like.

Description

Preparation of a quaternized nano-diamond agglomerated grafted anion chromatography packing method

technical field

The invention relates to a preparation method of anion chromatographic column packing.

Background technique

Ion chromatography, divided into cation exchange chromatography and anion exchange chromatography, is an important branch of high performance liquid chromatography. It has developed rapidly and has been widely used in agriculture, industry, environment, food, medicine and other analysis fields. The separation of ion chromatography mainly depends on the nature of the stationary phase, which consists of a matrix and functional groups with charged surfaces on its surface. At present, the widely used substrates are mainly silica gel and organic polymers. The silica gel skeleton is hard, the surface is easy to modify, and its pore size, surface area, exchange capacity and other parameters are easy to control. However, due to its narrow pH range (generally between 2-8 ) is mainly used for high-performance liquid chromatography; organic polymer substrates mainly include polystyrene-divinylbenzene, polyvinylbenzene-divinylbenzene, polymethacrylate, etc., and its pH has a wide range of applications (generally 1-14 Between), it is suitable for the mobile phase with acidity and alkalinity, but its mechanical strength still has certain deficiencies.

There are three main methods for surface ionization of organic polymer matrix chromatographic fillers, one is chemical derivation, the other is surface coating, and the third is electrostatic agglomeration. The chemical derivatization type includes the introduction of ion exchange sites on the surface of the matrix by chemical reaction, chemical grafting or hyperbranching. The direct chemical reaction has greater damage to the matrix microspheres and more by-products. Chemical grafting and hyperbranching methods are widely used due to their controllable exchange capacity and high separation efficiency. The surface coating type mainly refers to the combination of matrix microspheres and ion exchange layer through hydrophobic interaction, but the coating layer has poor stability and is easy to be lost during use. The electrostatic agglomeration type mainly agglomerates a charged ion exchange layer on the surface of the matrix through electrostatic interaction, and is widely used in the preparation of commercial columns due to its good stability and high separation efficiency. The agglomerates of agglomerated chromatographic fillers are usually organic polymer colloids with extremely small particles such as polystyrene, polyacrylate, etc. The surface charges of these colloidal particles require complex chemical modification, and the mechanical strength of the colloidal particles Insufficient, which also makes its application subject to certain restrictions. Nanodiamond has the advantages of high pressure resistance and acid and alkali resistance of organic polymers, and is a good choice for agglomerates on the surface of agglomerated chromatographic fillers.

Contents of the invention

The present invention aims at the shortcomings of insufficient latex mechanical strength on the surface of latex agglomeration-type chromatographic fillers, combined with the advantages of controllable exchange capacity of grafted chromatographic fillers, and provides a simple and efficient quaternized nano-diamond agglomerated grafted anion chromatography The preparation method of the filler, the prepared anion chromatography filler has the advantages of simplicity and high efficiency, good mechanical strength, controllable exchange capacity, high separation degree, strong acid and alkali resistance and the like.

In order to solve the problems of the technologies described above, the present invention adopts the following technical solutions:

A preparation method for quaternized nano-diamond agglomeration grafted anion chromatographic filler, comprising the following steps:

(a) Synthesize monodisperse linear polystyrene microspheres with a particle size between 1 and 3 μm;

(b) Synthesis of polystyrene-divinylbenzene microspheres by single-step seed swelling method: the monodisperse linear polystyrene microspheres were mixed with dibutyl phthalate to make monodisperse linear polystyrene microspheres Ball activation; then add monomer styrene, crosslinker divinylbenzene, emulsifier sodium lauryl sulfate, stabilizer polyvinyl alcohol, initiator benzoyl peroxide and porogen toluene for swelling; then heat Initiate the reaction to polymerize the monomer; then extract toluene to remove the porogen, and finally wash to obtain monodisperse polystyrene-divinylbenzene microspheres with a particle size of 6-10 μm;

(c) First oxidize nano-diamonds with a mixture of concentrated sulfuric acid and concentrated nitric acid to obtain carboxylated nano-diamonds with carboxyl groups on the surface, and then use methylamine and 1,4-butanediol diglycidyl ether as raw materials to quaternize them. Ammonization, and then dispersed in deionized water to obtain quaternized nano-diamond colloid;

(d) Agglomeration and grafting: first use 75-95% concentrated sulfuric acid as a sulfonating agent to sulfonate polystyrene-divinylbenzene microspheres to make the surface negatively charged, and then through electrostatic interaction with The positively charged quaternized nano-diamond colloids are combined to obtain an agglomerated anion-exchange packing; and then methylamine and 1,4-butanediol diglycidyl ether are used as raw materials to carry out the process on the surface of the microspheres of the agglomerated anion-exchange packing Grafting reaction to obtain quaternized nano-diamond agglomeration grafted anion chromatography filler.

In the step (a) of the present invention, it is recommended to adopt the emulsion dispersion polymerization method to synthesize monodisperse linear polystyrene microspheres, specifically: styrene is used as a monomer, polyvinylpyrrolidone is used as a stabilizer, and azobisisobutyronitrile is used as an initiator. In the reaction medium, monodisperse linear polystyrene microspheres are generated by free radical polymerization, the particle size is between 1 and 3 μm, the particle size is uniform, and no classification is required; the reaction medium is absolute ethanol or ethanol and water mixed solution.

Further, in the synthesis of the monodisperse linear polystyrene microspheres described in step (a), it is preferred to feed in the following manner: the quality of monomer styrene is 5 to 30% (m/m) of the mass of the reaction medium, preferably 25 %; the feed ratio of the stabilizer polyvinylpyrrolidone and the reaction medium is 0.5-4g: 100mL, preferably 1.6g: 100mL; the mass dosage of the initiator azobisisobutyronitrile is 1-5% of the monomer styrene mass dosage, Preferably 2.2%; in the mixture of ethanol and water, the volume concentration of ethanol is above 75%.

Further, in the synthesis of monodisperse linear polystyrene microspheres described in step (a), preferably free radical polymerization is carried out under stirring conditions, the reaction temperature is 40-85°C, preferably 80°C; the stirring speed is 100-400 revolution/minute; the reaction time is 8 to 24 hours, preferably 24 hours.

In step (b) of the present invention, in the activation of monodisperse linear polystyrene microspheres, the mass ratio of linear polystyrene microspheres to dibutyl phthalate is preferably 1:2 to 4, preferably 1:2 ; The activation temperature is 20-30°C, preferably 20°C; the activation time is 12-24 hours, preferably 24 hours.

In the step (b) of the present invention, the particle size of the monodisperse polystyrene-divinylbenzene microspheres is controlled by conditions such as porogen, crosslinking agent, stabilizer, swelling temperature, reaction temperature and swelling ratio It is preferably as follows: the mass consumption of monomer styrene is 10-20% (preferably 14%) of the total mass of the organic phase (made up of styrene, divinylbenzene, emulsifier, stabilizer, initiator and porogen), The mass ratio of the crosslinking agent divinylbenzene to monomer styrene is 1:9 to 3:1 (preferably 2:1), and the mass dosage of the emulsifier sodium lauryl sulfate accounts for 2 to 4% of the total mass of the organic phase ( Preferably 2.5%), the stabilizer polyvinyl alcohol quality consumption is 0.5～5% (preferably 1.5%) of the organic phase gross mass, and the initiator benzoyl peroxide quality consumption is 0.4～6% of the monomer styrene quality consumption ( Preferably 5-6%), the mass consumption of porogen toluene is 20-70% (preferably 50%) of the total mass of the organic phase; the swelling ratio is 10-70 times, and the swelling temperature is 20-35°C; the polymerization reaction is under stirring To carry out, the polymerization temperature is 60-85° C. (preferably 80° C.), the stirring speed is 100-300 rpm, and the reaction time is 12-48 hours (preferably 48 hours). The washing reagents are preferably water and ethanol. Under the above conditions, the particle size distribution of the synthesized polystyrene-divinylbenzene microspheres is very narrow, and the particle size range is between 6-10 μm. The synthesized microspheres are uniform and high, and classification and sieving are not required.

In the preparation of the quaternized nano-diamond colloid described in step (c) of the present invention, in the mixed acid of concentrated sulfuric acid and concentrated nitric acid, the volume ratio of concentrated sulfuric acid and concentrated nitric acid is 1:2-3, and the oxidation treatment temperature is 80-140°C , The treatment time is 8-12 hours.

In step (c) of the present invention, the quaternization reaction is carried out as follows: disperse the carboxylated nano-diamond in deionized water, add 2-10% (v/v) methylamine aqueous solution and react at 60-80°C for 1-8h (Preferably react at 70°C for 2 hours), filter and wash, then disperse in deionized water, add 2-20% (v/v) 1,4-butanediol diglycidyl ether aqueous solution and react at 60-80°C for 1- 8h (preferably react at 70°C for 2 hours), filter and wash to obtain quaternized nano-diamonds, and disperse them in a certain amount of deionized water to obtain quaternized nano-diamond colloids.

Further, in the preparation of the quaternized nano-diamond colloid in step (c), the mass ratio of the carboxylated nano-diamond to methylamine is preferably 1:1-2, and the carboxylated nano-diamond and 1,4-butanediol The mass ratio of glycidyl ether is 1:2~3.

In step (d) of the present invention, the agglomeration is carried out as follows: polystyrene-divinylbenzene microspheres are placed in 75-95% concentrated sulfuric acid, reacted at room temperature for 1-5min, and then diluted with water, filtered, and washed with deionized water until neutral to obtain sulfonated polystyrene-divinylbenzene microspheres; using deionized water as the medium, the sulfonated polystyrene-divinylbenzene The microsphere is mixed with the quaternized nano-diamond colloid, and the two are combined due to electrostatic interaction, and the agglomerated anion exchange filler is obtained after filtering and washing.

Further, in the agglomeration process described in step (d), the mass ratio of the sulfonated polystyrene-divinylbenzene microspheres to the quaternized nano-diamond is 2:0.5-2, preferably 3:1 .

In the step (d) of the present invention, the grafting reaction is carried out as follows: disperse the agglomerated anion exchange filler in deionized water, add 2-10% (v/v) methylamine aqueous solution at 50-70°C React for 1-8 hours, filter and wash, then disperse in deionized water, add 2-20% (v/v) 1,4-butanediol diglycidyl ether aqueous solution, react at 50-70°C for 1-8 hours, agglomerate Type anion exchange filler reacts alternately with methylamine aqueous solution and 1,4-butanediol diglycidyl ether aqueous solution according to the above steps, and by adjusting the number of reactions with methylamine and with 1,4-butanediol diglycidyl ether The exchange capacity of the chromatographic filler is controlled, and finally washed with deionized water to obtain the quaternized nano-diamond agglomeration grafted anion chromatographic filler.

Further, in the grafting reaction described in step (d), the mass ratio of the anion exchange filler to methylamine in each reaction step is preferably 1:0.2 to 1, preferably 1:0.4, and the anion filler to 1 in each step reaction. The mass ratio of 4-butanediol diglycidyl ether is 1:2-4, preferably 1:3.

Compared with prior art, the present invention has following advantage:

(1) The present invention adopts polystyrene-divinylbenzene microspheres as a matrix, and provides a novel surface agglomeration grafted chromatographic filler with stable chromatographic performance and high separation efficiency. The preparation process is simple, the cost is low, and the particle size Even without sieving, the filler has good acid and alkali resistance, and is applicable in the range of pH 1-14.

(2) the method for preparing the quaternized nano-diamond colloid provided by the invention is simple, and compared with the organic polymer colloid of small particles, the hardness of the nano-diamond colloid is strong, so the anion-exchange chromatographic filler prepared by the present invention has better mechanical properties strength.

(3) The preparation method of the anion exchange chromatographic filler provided by the present invention adopts the method of first agglomeration and then grafting, and its ion exchange capacity can be controlled on demand, and is used to prepare ion chromatography columns with different exchange capacities; the prepared surface-grafted The dendritic chromatographic column can be used in ion exchange chromatography stably for a long time, and can rapidly separate F ^- , Cl ^- , SO ₄ ^2- , NO ₂ ^- , Br ^- , PO ₄ ^3- , NO ₃ ^- seven kinds of anions.

Description of drawings

Fig. 1 is the scanning electron micrograph (magnified 4000 times) of the polystyrene-divinylbenzene microsphere synthesized in embodiment 1.

Fig. 2 is the scanning electron micrograph of the filler microsphere after the agglomerated nano-diamond synthesized in Example 1 (4000 times magnification).

Fig. 3 is the chromatogram of 7 kinds of anions separated by the packing material synthesized in embodiment 1; Wherein, (1) F ^- 2ppm, (2) Cl ^- 5ppm, (3) NO ₂ ^- 10ppm, (4) Br ^- 20ppm, (5 ) NO ₃ ^- 20ppm, (6) PO ₄ ^3- 30ppm, (7) SO ₄ ^2- 10ppm.

Fig. 4 is the chromatogram of 7 kinds of anions separated by the packing material synthesized in embodiment 2; Wherein, (1) F ^- 2ppm, ( ₂ ) Cl ^- 5ppm, (3) NO 2-10ppm ^{, (4) Br- 20ppm} , (5 ) NO ₃ ^- 20ppm, (6) PO ₄ ^3- 30ppm, (7) SO ₄ ^2- 10ppm.

detailed description

The technical scheme of the present invention will be further described below with specific examples, but protection scope of the present invention is not limited to this:

Embodiment 1: the synthesis of anion exchange filler

1. Synthesis of monodisperse polystyrene seeds: Add 90% ethanol aqueous solution to the flask, then add the stabilizer polyvinylpyrrolidone, heat the water bath to 80°C, then add styrene monomer and initiator azobisisobutyl Nitrile, stirred for 24 hours. Wherein the quality of monomer styrene is 25% (m/m) of the ethanol aqueous solution quality, the stabilizer polyvinylpyrrolidone quality is 1.6% (m/v) of the ethanol aqueous solution volume, and the initiator azobisisobutyronitrile quality is mono 2.2% (m/m) of the bulk styrene mass, the reaction medium is 90% ethanol aqueous solution, the stirring speed is 300 rpm, and after filtering and washing, polystyrene seeds with a particle size of 2 μm are obtained.

2. Synthesis of polystyrene-divinylbenzene microspheres: Take the polystyrene seeds in step 1 and dibutyl phthalate and mix them in a flask, stir for 24 hours at 20°C, and the stirring speed is 200 rpm Minutes, wherein the mass ratio of polystyrene seeds and dibutyl phthalate is 2:4; configure the organic phase, the quality of monomer styrene in this organic phase is 14% (m/m) of the total mass of the organic phase, The mass ratio of the crosslinking agent divinylbenzene to styrene is 2:1, the mass of the emulsifier sodium lauryl sulfate is 2.5% (m/m) of the total mass of the organic phase, and the mass of the stabilizer polyvinyl alcohol is 1.5% (m/m) of the total mass of the organic phase, the quality of the initiator benzoyl peroxide is 0.8% (m/m) of the total mass of the organic phase, and the quality of the porogen toluene is 50% of the total mass of the organic phase (m/m); Add the prepared organic phase to the flask, stir at 20°C for 24 hours, the stirring speed is 200 rpm, and the swelling ratio is 55; then heat up to 80°C for reaction, the stirring speed is 200 rpm, and the reaction time After 48 hours, polystyrene-divinylbenzene microspheres with a particle size of 6-10 μm were obtained, and the polymer microspheres were extracted with toluene to remove the porogen, and then washed with water and ethanol;

3. Using 95% concentrated sulfuric acid as a sulfonating agent, mix and react with the polystyrene divinylbenzene microspheres synthesized in step 2 at room temperature for 3 minutes, dilute with ice water, filter, and wash with deionized water until neutral.

4. Mix concentrated sulfuric acid and concentrated nitric acid in a flask at a volume ratio of 1:2 to obtain a strong oxidizing mixed acid solution, add nano-diamonds and raise the temperature to 100 ° C for 12 hours, filter and wash to obtain carboxylated nano-diamonds; carboxylated nano-diamonds Disperse in a certain amount of deionized water, add 4% methylamine aqueous solution, in which the mass ratio of carboxylated nano-diamond and methylamine is 1:1, heat up to 70°C for 2 hours, filter and wash, then disperse in a certain amount of deionized Add 15% aqueous solution of 1,4-butanediol diglycidyl ether to water, wherein the mass ratio of carboxylated nano-diamonds to 1,4-butanediol diglycidyl ether is 1:2, heat up to 70°C for reaction After 2 hours, filter and wash to obtain the quaternized nano-diamond, disperse the quaternized nano-diamond in a certain amount of deionized water to obtain the quaternized nano-diamond colloid, the colloid and the sulfonated microspheres in step 3 according to the quaternized Ammonium nano-diamond and microspheres were mixed at a mass ratio of 1:3 and stirred at room temperature for 24 hours, filtered and washed to obtain agglomerated nano-diamond microspheres; the microspheres were dispersed in a certain amount of deionized water, heated to 70°C, and added Concentration is the methylamine aqueous solution of 4% (v/v), make the feeding mass ratio of microspheres and methylamine be 1:0.4, react for 1 hour, after filtering and washing, disperse the microspheres in a certain amount of deionized water, heat up To 70°C, add 1,4-butanediol diglycidyl ether aqueous solution with a concentration of 15% (v/v), so that the mass ratio of microspheres to 1,4-butanediol diglycidyl ether is 1 : 3, reacted 1 hour; Use methylamine and 1,4-butanediol diglycidyl ether alternately to react once again according to the above-mentioned steps successively, obtain the anion-exchange filler of grafting 2 times, the filler obtained is deionized water Wash, and then use the homogenate method to pack the column;

5. Using the mobile phase of sodium carbonate and sodium bicarbonate system, the flow rate is 1mL/min to analyze 7 kinds of conventional anions.

Embodiment 2: with reference to the method and steps of embodiment 1

1. Synthesis of monodisperse polystyrene seeds: Add 90% ethanol aqueous solution to the flask, then add the stabilizer polyvinylpyrrolidone, heat the water bath to 80°C, then add styrene monomer and initiator azobisisobutyl Nitrile, stirred for 24 hours. Wherein the quality of monomer styrene is 25% (m/m) of the ethanol aqueous solution quality, the stabilizer polyvinylpyrrolidone quality is 1.6% (m/v) of the ethanol aqueous solution volume, and the initiator azobisisobutyronitrile quality is mono 2.2% (m/m) of the bulk styrene mass, the reaction medium is 90% ethanol aqueous solution, the stirring speed is 300 rpm, and after filtering and washing, polystyrene seeds with a particle size of 2 μm are obtained.

2. Synthesis of polystyrene-divinylbenzene microspheres: Take the polystyrene seeds in step 1 and dibutyl phthalate and mix them in a flask, stir for 24 hours at 20°C, and the stirring speed is 200 rpm Minutes, wherein the mass ratio of polystyrene seeds and dibutyl phthalate is 2:4; configure the organic phase, the quality of monomer styrene in this organic phase is 14% (m/m) of the total mass of the organic phase, The mass ratio of the crosslinking agent divinylbenzene to styrene is 2:1, the mass of the emulsifier sodium lauryl sulfate is 2.5% (m/m) of the total mass of the organic phase, and the mass of the stabilizer polyvinyl alcohol is 1.5% (m/m) of the total mass of the organic phase, the quality of the initiator benzoyl peroxide is 0.8% (m/m) of the total mass of the organic phase, and the quality of the porogen toluene is 50% of the total mass of the organic phase (m/m); Add the prepared organic phase to the flask, stir at 20°C for 24 hours, the stirring speed is 200 rpm, and the swelling ratio is 55; then heat up to 80°C for reaction, the stirring speed is 200 rpm, and the reaction time After 48 hours, polystyrene-divinylbenzene microspheres with a particle size of 6-10 μm were obtained, and the polymer microspheres were extracted with toluene to remove the porogen, and then washed with water and ethanol;

3. Using 95% concentrated sulfuric acid as a sulfonating agent, mix and react with the polystyrene divinylbenzene microspheres synthesized in step 2 at room temperature for 3 minutes, dilute with ice water, filter, and wash with deionized water until neutral.

4. Mix concentrated sulfuric acid and concentrated nitric acid in a flask at a volume ratio of 1:2 to obtain a strong oxidizing mixed acid solution, add nano-diamonds and raise the temperature to 100°C for 12 hours, filter and wash to obtain carboxylated nano-diamonds; carboxylated nano-diamonds Disperse in a certain amount of deionized water, add 4% methylamine aqueous solution, in which the mass ratio of carboxylated nano-diamond and methylamine is 1:1, heat up to 70°C for 2 hours, filter and wash, then disperse in a certain amount of deionized In water, add 15% aqueous solution of 1,4-butanediol diglycidyl ether, wherein the mass ratio of carboxylated nano-diamonds to 1,4-butanediol diglycidyl ether is 1:2, heat up to 70°C for reaction After 2 hours, filter and wash to obtain the quaternized nano-diamond, disperse the quaternized nano-diamond in a certain amount of deionized water to obtain the quaternized nano-diamond colloid, the colloid and the sulfonated microspheres in step 3 according to the quaternized Mix ammonium nano-diamond and microspheres at a mass ratio of 1:3, stir at room temperature for 24 hours, filter and wash to obtain agglomerated nano-diamond microspheres; disperse the microspheres in a certain amount of deionized water, heat up to 70°C, add Concentration is the methylamine aqueous solution of 4% (v/v), make the feeding mass ratio of microsphere and methylamine be 1:0.4, react for 1 hour, after filtering and washing, disperse the microsphere in a certain amount of deionized water, heat up To 70°C, add 1,4-butanediol diglycidyl ether aqueous solution with a concentration of 15% (v/v), so that the mass ratio of microspheres to 1,4-butanediol diglycidyl ether is 1 : 3, reacted 1 hour; Use methylamine and 1,4-butanediol diglycidyl ether alternately to react twice again according to the above-mentioned steps, obtain the anion-exchange filler of grafting 3 times, the filler obtained is deionized Wash with water, and then use the homogenate method to pack the column;

5. Using the mobile phase of sodium carbonate and sodium bicarbonate system, the flow rate is 1mL/min to analyze 7 kinds of conventional anions.

Embodiment 3: Chromatographic column performance test

Instrument: Dionex ICS-1100

Sample: sodium fluoride, sodium bromide, sodium nitrate, sodium nitrite, sodium phosphate, ammonium sulfate and sodium chloride

Separation column: stainless steel column (150×4.6mm)

Eluent: 2mmol/L sodium carbonate and 2mmol/L sodium bicarbonate

Flow rate: 1mL/min

Detector: Conductivity detector

Suppressor: Dionex ASRS ^@ 300 4-mm, suppression current 50mA

See Figure 3 and Figure 4 for the separation chromatogram, where (1) F ^- 2ppm, (2) Cl ^- 5ppm, (3) NO ₂ ^- 10ppm, (4) Br ^- 20ppm, (5) NO ₃ ^- 20ppm, (6 )PO ₄ ^3-30ppm , (7)SO ₄ ^2-10ppm .

Fig. 1 is the scanning electron micrograph (magnification 4000 times) of the polystyrene-divinylbenzene microsphere that embodiment 1 makes, and it can be seen that its surface is relatively smooth in the figure, and particle diameter is at 6-8 μ m.

Fig. 2 is the scanning electron micrograph (magnification 4000 times) of the filler microsphere after the agglomerated nano-diamond that embodiment 1 makes, compares with Fig. 1, obviously can see that its surface has the shell that one deck uniform nano-diamond forms , indicating that the agglomeration is successful and can play the role of anion exchange.

Fig. 3 is the chromatogram of the separation of seven kinds of anions by the filler microspheres that have been agglomerated with nano-diamonds and then grafted twice, and can successfully separate seven kinds of anions within 15 minutes. The separation speed is fast and can meet the requirements. Qualitative and quantitative testing requirements.

Fig. 4 is the chromatogram of the separation of seven kinds of anions by the filler microspheres obtained in Example 2 after the agglomeration of nano-diamonds and grafting reaction three times, and seven kinds of anions can be successfully separated within 25 minutes. Compared with Fig. 3, it can be found With the increase of the number of grafting reactions, the exchange capacity and resolution of the column were improved.

Claims (10)

1. a kind of preparation method of quaternized Nano diamond agglomeration graft type anion chromatographic filling material, comprises the following steps：

(a) monodispersed linear polystyrene microballoon of the synthesis particle diameter between 1~3 μm；

(b) using single step seed swelling method synthetic polystyrene-divinylbenzene microspheres：By the monodispersed linear polyphenyl of synthesis Ethene microballoon is mixed with dibutyl phthalate activates single dispersing linear polystyrene microballoon；It is subsequently added monomer benzene second Alkene, cross-linker divinylbenzene, emulsifier sodium lauryl sulfate, stabilizer polyvinyl alcohol, initiator benzoyl peroxide and Pore-foaming agent toluene is swelled；Then heating initiation reaction polymerize monomer；Pore-foaming agent is removed by toluene extracting again, is most passed through afterwards Washing obtains monodispersed polystyrene-divinylbenzene microspheres of the particle diameter between 6-10 μm；

(c) first Nano diamond is aoxidized with the mixed liquor of the concentrated sulfuric acid and concentrated nitric acid, obtains carboxylated nanometer of the surface with carboxyl Diamond, then using methylamine and BDDE it is carried out as raw material quaternized, it is then dispersed in deionization Quaternized Nano diamond colloid is obtained in water；

(d) agglomeration and grafting：First the concentrated sulfuric acid using 75~95% enters as sulfonated reagent to polystyrene-divinylbenzene microspheres Row sulfonation, makes its surface negatively charged, then is combined by electrostatic interaction with the quaternized Nano diamond colloid of positively charged, obtains Agglomeration type anion exchange filler；It is again raw material in agglomeration type anion exchange using methylamine and 1,4- butanediol diglycidyl ethers The microsphere surface of filler carries out graft reaction, obtains quaternized Nano diamond agglomeration graft type anion chromatographic filling material.

2. preparation method as claimed in claim 1, it is characterised in that：In step (a), synthesize single using emulsion dispersion polymerization Scattered linear polystyrene microballoon, be specially：Using styrene as monomer, polyvinylpyrrolidone is used as stabilizer, azo two Isobutyronitrile is initiator, generates monodispersed linear polystyrene microballoon by radical polymerization in reaction medium, particle diameter is 1 Between~3 μm；The reaction medium is the mixed liquor of absolute ethyl alcohol or second alcohol and water；

Wherein, the quality of monomer styrene is the 5~30% of reaction medium quality；Stabilizer polyvinylpyrrolidone is situated between with reaction The rate of charge of matter is 0.5~4g：100mL；Initiator azodiisobutyronitrile quality consumption for monomer styrene quality consumption 1~ 5%；In the mixed liquor of second alcohol and water, ethanol volumetric concentration is more than 75%；

Radical polymerization is carried out under agitation, and reaction temperature is 40~85 DEG C；Mixing speed is at 100~400 revs/min； Reaction time is 8~24 hours.

3. preparation method as claimed in claim 1, it is characterised in that：In step (b), single dispersing linear polystyrene microballoon In activation, the mass ratio of linear polystyrene microballoon and dibutyl phthalate is 1：2~4, activation temperature is 20~30 DEG C, Soak time is 12~24 hours.

4. preparation method as claimed in claim 1, it is characterised in that：In step (b), monomer styrene quality consumption is organic The mass ratio of the 10~20% of phase gross mass, crosslinking agent divinylbenzene and monomer styrene is 1:9~3:1, emulsifying agent dodecane Base sodium sulfate quality consumption accounts for the 2~4% of organic phase gross mass, and stabilizer polyvinyl alcohol quality consumption is organic phase gross mass 0.5~5%, initiator benzoyl peroxide quality consumption is the 0.4~6% of monomer styrene quality consumption, pore-foaming agent toluene Quality consumption is the 20~70% of organic phase gross mass；The organic phase by styrene, divinylbenzene, emulsifying agent, stabilizer, draw Send out agent and pore-foaming agent composition；

Swelling temperature is 20~35 DEG C, and swelling ratio is 10~70 times；Polymerisation is carried out under agitation, and polymerization temperature is 60~85 DEG C, 100~300 revs/min of mixing speed, 12~48 hours reaction time.

5. preparation method as claimed in claim 1, it is characterised in that：In step (c), the mixed liquor of the concentrated sulfuric acid and concentrated nitric acid In, the volume ratio of the concentrated sulfuric acid and concentrated nitric acid is 1：2~3, oxidation temperature is 80~140 DEG C, and processing time is 8~12 small When.

6. preparation method as claimed in claim 1, it is characterised in that：In step (c), quaterisation is according to being implemented as follows： Carboxylated Nano diamond is scattered in deionized water, the methylamine water solution that addition volume fraction is 2~10% is 60~80 DEG C 1~8h of reaction, is redispersed in deionized water after filtration washing, adds the BDO two that volume fraction is 2~20% The glycidol ether aqueous solution reacts 1~8h in 60~80 DEG C, and filtration washing obtains quaternized Nano diamond, is scattered in one Quaternized Nano diamond colloid is obtained in quantitative deionized water；

Wherein, the mass ratio that feeds intake of carboxylated Nano diamond and methylamine is 1：1~2, carboxylated Nano diamond and Isosorbide-5-Nitrae-fourth The mass ratio that feeds intake of Hexanediol diglycidyl ether is 1：2~3.

7. preparation method as claimed in claim 1, it is characterised in that：In step (d), described agglomeration is proceeded as follows： Polystyrene-divinylbenzene microspheres are placed in 75~95% concentrated sulfuric acid, 1~5min is reacted at room temperature, ice is then used Water dilutes, filtering, then is washed with deionized water to neutrality, obtains the polystyrene-divinylbenzene microspheres after sulfonation；With deionization Water is medium, and the polystyrene-divinylbenzene microspheres after sulfonation are mixed with quaternized Nano diamond colloid, both due to Electrostatic interaction is combined, and agglomeration type anion exchange filler is obtained after filtration washing.

8. preparation method as claimed in claim 7, it is characterised in that：In step (d) agglomeration process, the polyphenyl after sulfonation The mass ratio that feeds intake of ethene-divinylbenzene microspheres and quaternized Nano diamond is 2:0.5~2.

9. preparation method as claimed in claim 1, it is characterised in that：In step (d) of the present invention, described graft reaction according to It is carried out as follows：Agglomeration type anion exchange filler is scattered in deionized water, the methylamine water that volume fraction is 2~10% is added Solution is redispersed in deionized water after reacting 1~8h, filtration washing at 50~70 DEG C, and it is 2~20% to add volume fraction The BDDE aqueous solution reacts 1~8h, agglomeration type anion exchange filler and methylamine water in 50~70 DEG C Solution and the BDDE aqueous solution press above-mentioned steps alternation response, and by adjustment with methylamine and with 1, The reaction times of 4- butanediol diglycidyl ethers control the exchange capacity of chromatograph packing material, are finally washed with deionized and obtain Quaternized Nano diamond agglomeration graft type anion chromatographic filling material.

10. preparation method as claimed in claim 9, it is characterised in that：In step (d) graft reaction, in often step reaction The mass ratio that feeds intake of anion exchange filler and methylamine is 1：0.2~1；Anion filler and 1,4- butanediols two in often step reaction The mass ratio that feeds intake of glycidol ether is 1：2~4.